Sealed connection between an optical fibre cable and a submerged housing

Abstract

The invention relates to a sealed connection between an optical fibre line cable (C) and an electronics-containing submerged housing (11) the connection being via an access provided in a cover (1) which closes the housing. The connection is constituted by a length of optical fibre cable called the lead-in cable (2), installed on the electronics block and including thereon a notched hollow tube (7) which surrounds the cable together with connection ring (10) which extends the notched part towards the inside of the housing; one end of which is fixed to the notched part (7), the other forming a stop for the cover, the connecting ring co-operating with means (19) for locking the cover against the stop, said connection including outer casings (16, 23, 22) which provide continuity of the seal between the lead-in cable and the housing of the repeater.

I claim: 
     
       1. A sealed connection between an optical fibre cable, the "line cable", and an underwater housing in the form of a cylinder closed at each end by a respective cover and containing an electronics block, the connection being made through one of the covers via an access provided therein, and comprising: a single length of optical fibre cable, "the lead-in cable" connected at one end to the line cable and at the other end to the electronics block; and   a hollow member threaded on the lead-in cable where it passes through the access in the cover, the outside end of the hollow member and an adjacent length of the lead in cable being embedded in a first sealed casing; the inside end of the hollow member forming a stop for the cover when the cover is in the closed position and being connected by annular bellows to an adjacent end wall of the electronics block; and an intermediate portion of the hollow member being engaged with locking means for locking the lead-in cable in the access through the cover when the cover is in the closed position, sealing means being provided at the access which sealing means are held in position by said locking means.   
     
     
       2. A sealed connection according to claim 1, wherein the said hollow member is constituted by a tube having a notched outer surface, i.e. a surface which is crenellated in axial cross-section, and by a connecting ring which extends the notched tube towards the interior of the housing, the connecting ring being mechanically connected to the notched tube by means interposing a first seal ring between the notched tube and the connecting ring; the connection further including a socket fixed to the cover and extending outwardly the access therethrough, said socket holding the locking means around the connecting ring and trapping a second seal ring between the cover and the connecting ring; the connection being covered by at least one second sealed casing providing together with the first sealed casing continuity of sealing between the lead-in cable and the cover, and constituting, together with the said first and second seal rings, the said sealing means. 
     
     
       3. A sealed connection according to claim 2, wherein the notched tube has a collar with a peripheral groove in which said first seal ring is recessed, the collar being covered by the corresponding end of said connecting ring whose inner surface is staggered correspondingly. 
     
     
       4. A sealed connection according to claim 2 or 3, including a closing ring installed on the end of said socket and on the end of said connecting ring where it is connected to the notched tube, said closing ring closing the access through said cover and fixing said means for locking the cover on the connecting ring. 
     
     
       5. A sealed connection according to claim 2 or 3, wherein said locking means are constituted by a nut installed on the connecting ring which is threaded to co-operate therewith. 
     
     
       6. A sealed connection according to claim 1, wherein said hollow member is constituted by a single tube having a notched outer surface which surface also has several stages of increasing diameter going from the outside end towards the inside of said housing; the last stage inside said housing forming said stop for said cover, the penultimate stage holding said sealing means between it and the cover, and the antepenultimate stage being threaded and co-operating with a nut to constitute said locking means. 
     
     
       7. A sealed connection according to claim 6, further including a first toroidal part made of soft metal, a second toroidal part made of hard metal which is fitted into the first and a thrust washer between said nut and said second toroidal part to provide self-tightening of said locking means, said parts being recessed in a peripheral clearance of the cover, said clearance being open in the access and towards the outside of the housing.